63 results match your criteria: "Lanzhou University Lanzhou 730000 China.[Affiliation]"

Strong electronic interaction enhanced electrocatalysis of copper phthalocyanine decorated Co-MOF-74 toward highly efficient oxygen evolution reaction.

RSC Adv

December 2024

State Key Laboratory of Applied Organic Chemistry, Laboratory of Special Function Materials and Structure Design of the Ministry of Education, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China.

Metal-organic frameworks (MOFs) have been identified as promising electrocatalysts for the oxygen evolution reaction (OER). However, most of the reported MOFs have low electrical conductivity and poor stability, and therefore addressing these problems is crucial for achieving higher electrocatalytic performance. Meanwhile, direct observations of the electrocatalytic behavior, which is of great significance to the understanding of the electrocatalytic mechanism, remain highly challenging.

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Article Synopsis
  • Pyruvate kinase M2 (PKM2) is an important enzyme that is often overexpressed in cancer cells, making it a target for cancer treatments aimed at blocking glycolysis.
  • The study identifies plumbagin, a compound from a plant, as a novel inhibitor of PKM2, which decreases its activity and leads to reduced expression of related downstream genes in HepG2 cancer cells.
  • Plumbagin also induces oxidative stress and mitochondrial damage, resulting in increased apoptosis, while simultaneously decreasing cell migration and proliferation, highlighting its potential as an anticancer therapeutic.
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Intermolecular sulfur atom transfer cascade enabled late-stage introduction of sulfilimines into peptides.

Chem Sci

September 2024

Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences & Research Unit of Peptide Science, Chinese Academy of Medical Sciences, 2019RU066, Lanzhou University Lanzhou 730000 China

Sulfilimines, a privileged class of -S(iv)[double bond, length as m-dash]N- functional groups found in nature, have been exploited as valuable building blocks in organic synthesis and as pharmacophores in drug discovery, and have aroused significant interest in the chemical community. Nevertheless, strategies for late-stage introduction of sulfilimines into peptides and proteins have still met with limited success. Herein, we have developed a method of introducing biological sulfilimine fragments into peptides by an intermolecular sulfur atom transfer cascade reaction, utilizing hydroxylamine condensed with the acid moieties of peptides and varied diaryl disulfides.

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Controllable β-carbon elimination to extrude norbornene remains a long-standing challenge in palladium and norbornene chemistry. Herein, this manuscript describes a switchable synthesis of biologically active C4-ethylaminoindole and C7-aminoindoline scaffolds by controlling β-carbon elimination, utilizing aziridine as a C-H ethylamination reagent through a C-N bond cleavage reaction. Furthermore, the protecting groups of the product can be easily removed, offering an unusual method for the synthesis of dopamine receptor agonists.

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Cyclic peptides represent invaluable scaffolds in biological affinity, providing diverse collections for discovering functional molecules targeting challenging biological entities and protein-protein interactions. The field increasingly focuses on developing cyclization strategies and chemically modified combinatorial libraries in conjunction with M13 phage display, to identify macrocyclic peptide inhibitors for traditionally challenging targets. Here, we introduce a cyclization strategy utilizing -phthalaldehyde (OPA) for the discovery of active macrocycles characterized by asymmetric scaffolds with side-chain cyclization.

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Late-stage modification of peptides could potentially endow peptides with significant bioactivity and physicochemical properties, and thereby provide novel opportunities for peptide pharmaceutical studies. Since tryptophan (Trp) bears a unique indole ring residue and plays various critical functional roles in peptides, the modification methods for tryptophan were preliminarily developed with considerable progress transition-metal mediated C-H activation. Herein, we report an unprecedented tertiary amine catalyzed peptide allylation the S2'-S2' pathway between the N1 position of the indole ring of Trp and Morita-Baylis-Hillman (MBH) carbonates.

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At present, mainstream room-temperature phosphorescence (RTP) emission relies on organic materials with long-range charge-transfer effects; therefore, exploring new forms of charge transfer to generate RTP is worth studying. In this work, indole-carbazole was used as the core to ensure the narrowband fluorescence emission of the material based on its characteristic short-range charge-transfer effect. In addition, halogenated carbazoles were introduced into the periphery to construct long-range charge transfer, resulting in VTCzNL-Cl and VTCzNL-Br.

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Efficient separation of uranium from seawater stands as a pivotal challenge. This study unveils an approach focusing on the ingenious design of biomimetic two-dimensional (2D) membranes tailored explicitly for this purpose. Leveraging the unique interplay of DNA strands housing U aptamers, pH-responsive i-motifs, and poly A segments ingeniously embedded within graphene oxide membranes, a distinctive biomimetic 2D channel is engineered.

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Electrocatalytic nitrate (NO) reduction reaction (eNORR) to ammonia under ambient conditions is deemed a sustainable route for wastewater treatment and a promising alternative to the Haber-Bosch process. However, there is still a lack of efficient electrocatalysts to achieve high NH production performance at wastewater-relevant low NO concentrations. Herein, we report a PdRu bimetallic nanocrystal (NC) electrocatalyst capable of exhibiting an average NH FE of ∼100% over a wide potential window from 0.

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The field of metal-organic frameworks (MOFs) includes a vast number of hybrid organic and inorganic porous materials with wide-ranging applications. In particular, the Cu(i) ion exhibits rich coordination chemistry in MOFs and can exist in two-, three-, and four-coordinate environments, which gives rise to many structural motifs and potential applications. Direct characterization of the structurally and chemically important Cu(i) local environments is essential for understanding the sources of specific MOF properties.

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Site selective functionalization of inert remote C(sp)-H bonds to increase molecular complexity offers vital potential for chemical synthesis and new drug development, thus it has been attracting ongoing research interest. In particular, typical β-C(sp)-H arylation methods using chelation-assisted metal catalysis or metal-catalyzed oxidative/photochemical generated allyl C(sp)-H bond processes have been well developed. However, radical-mediated direct β-C(sp)-H arylation of carbonyls remains elusive.

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Near-infrared red (NIR) fluorescence imaging guide phototherapeutic therapy (PDT) has the advantages of deep tissue penetration, real-time monitoring of drug treatment and disease, little damage to normal tissue, low cytotoxicity and almost no side effects, and thus, it is attracting increasing research attention and is expected to show promising potential for clinical tumor treatment. The photosensitizer (PS), light source and oxygen are the three basic and important factors to construct PDT technology, and highly efficient PSs are still being passionately pursued because they determine the PDT efficiency. Ideal PSs should have properties such as good biocompatibility, deep tissue penetration, and highly efficient reactive oxygen species (ROS) generation despite the hypoxic environment.

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Synthesis, supramolecular aggregation, and NIR-II phosphorescence of isocyanorhodium(i) zwitterions.

Chem Sci

October 2023

Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province, State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China

Development of new second near-infrared (NIR-II, 1000-1700 nm) luminophores is highly desirable, and d square-planar metal complexes with NIR-II phosphorescence have been rarely reported. Herein, we explore an asymmetric coordination paradigm to achieve the first creation of NIR-II phosphorescent isocyanorhodium(i) zwitterions. They show a strong tendency for aggregation in solution, arising from close Rh(i)⋯Rh(i) contacts that are further intensified by π-π stacking interactions and the hydrophilic-hydrophobic effect.

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Visible-light-promoted site-selective and direct C-F bond functionalization of polyfluorinated iminosulfides was accomplished with alkenes and water under redox-neutral conditions, affording a diverse array of γ-lactams with a fluoro- and perfluoroalkyl-substituted carbon centre. A variety of perfluoroalkyl units, including CF, CF, CF, and CF underwent site-selective defluorofunctionalization. This protocol allows high chemoselectivity control and shows excellent functional group tolerance.

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Solvatomorphism and first-time observation of acid-acid catemer in 4-phenylamino-benzoic acids.

RSC Adv

July 2023

Key Laboratory for Green Chemical Process of Ministry of Education, Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, Hubei Engineering Research Center for Advanced Fine Chemicals, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology 206 1st Rd Optics Valley, East Lake New Technology Development District Wuhan Hubei 430205 China +86 027 87194980.

To investigate the polymorphism in 4-phenylamino-benzoic acids (4-PABAs) in general, and the effect on the polymorphism of these compounds exerted by substitution in particular, a series of 4-PABAs (1-8) varying in the substitution position and pattern were synthesized, and their polymorphic behavior was investigated for the first time. A relatively comprehensive polymorph screening led to the discovery of two forms, one solvent-free and the other solvate, for compounds 1, 3 and 8, and one form for the other compounds. The crystal structures were determined by single-crystal XRD.

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The first enantioselective total syntheses of six natural and two proposed meroterpenoids isolated from have been achieved in 7-9 steps from 2-methylcyclohexanone. The current synthetic approaches feature a high level of synthetic flexibility, stereodivergent fashion and short synthetic route, thereby providing a potential platform for the preparation of numerous this-type meroterpenoids and their -natural products.

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We report the self-assembly of amphiphilic BDQ photosensitizers into lysosome-targeting nanophotosensitizer BDQ-NP for highly effective photodynamic therapy (PDT). Molecular dynamics simulation, live cell imaging, and subcellular colocalization studies showed that BDQ strongly incorporated into lysosome lipid bilayers to cause continuous lysosomal membrane permeabilization. Upon light irradiation, the BDQ-NP generated a high level of reactive oxygen species to disrupt lysosomal and mitochondrial functions, leading to exceptionally high cytotoxicity.

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Tungsten disulfide (WS) is promising for potential applications in transistors and gas sensors due to its high mobility and high adsorption of gas molecules onto edge sites. This work comprehensively studied the deposition temperature, growth mechanism, annealing conditions, and Nb doping of WS to prepare high-quality wafer-scale N- and P-type WS films by atomic layer deposition (ALD). It shows that the deposition and annealing temperature greatly influence the electronic properties and crystallinity of WS, and insufficient annealing will seriously reduce the switch ratio and on-state current of the field effect transistors (FETs).

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The effectiveness of photocatalysts can be impacted by the high compounding efficiency of photogenerated carriers, which depends on the morphology of the photocatalyst. Here, a hydrangea-like N-ZnO/BiOI composite has been prepared for achieving efficient photocatalytic degradation of tetracycline hydrochloride (TCH) under visible light. The N-ZnO/BiOI exhibits a high photocatalytic performance, degrading nearly 90% of TCH within 160 min.

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The theories of sympatric speciation (SS) and coding and noncoding (cd and ncd =repeatome)  genome function are still contentious. Studies on SS in our two new models, "Evolution Canyon" and "Evolution Plateau", in Israel, divergent microclimatically and geologically-edaphically, respectively, indicated that in ecologically divergent microsites SS is a common speciation model across life from bacteria to mammals. Genomically, the intergenic ncd repeatome was and is still regarded by many biologists as "selfish," "junk," and non-functional.

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Hyperuricemia is a disease caused by disorder of purine metabolism, mainly due to insufficient renal excretion of uric acid. Urate transporter 1 (URAT1) is the most widely studied target of urate transporters, and used for uric acid (UA) reabsorption. This study used the AlphaFold2 algorithm to predict the structure of URAT1.

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Robust singlet fission process in strong absorption π-expanded diketopyrrolopyrroles.

Chem Sci

November 2022

Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China.

Singlet fission (SF) has drawn tremendous attention as a multiexciton generation process that could mitigate the thermal loss and boost the efficiency of solar energy conversion. Although a SF-based solar cell with an EQE above 100% has already been fabricated successfully, the practical efficiency of the corresponding devices is plagued by the limited scope of SF materials. Therefore, it is of great importance to design and develop new SF-capable compounds aiming at practical device application.

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Bile acids (BAs) containing both hydrophilic hydroxyl and carboxyl groups and hydrophobic methyl and steroid nuclei can promote the absorption of fat and other substances in the intestine, and they are synthesized by cholesterol in the liver and then returned to the liver through enteric liver circulation. Because there are many BA receptors on the cell membrane of colon tissues, BAs can improve the specific delivery and transport of medicines to colon tissues. Moreover, BAs have a certain anticancer and inflammation activity by themselves.

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Flavanthrene derivatives as photostable and efficient singlet exciton fission materials.

Chem Sci

August 2022

State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China

Singlet exciton fission (SF) is believed to have the potential to break the Shockley-Queisser limit for third-generation solar cell devices, so it has attracted great attention. Conventional linear acene based SF materials generally suffer from low triplet energy and poor photostability. We report herein two flavanthrene derivatives, EH-Fla and TIPS-Fla, as new photostable singlet exciton fission materials.

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Metronidazole is a specific drug against trichomonas and anaerobic bacteria, and is widely used in the clinic. However, extensive clinical application is often accompanied by extensive side effects, so it is still of great significance to develop metronidazole derivatives with a new skeleton. Compared with other traditional receptor-based drug design methods, the computational model based on a neural network has higher accuracy and reliability.

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